Here are some links to help set up NFS on MacOS X.

Mac OS X as an NFS Client

This is an excellent reference by Bryan Blackburn.

Mac OS X as an NFS Server

Another excellent reference by Bryan Blackburn.

NFS Commander

This is a project that I started that hasn't gotten any attention after it worked well enough for me to create a few mounts ;) I'm using Linux as my main OS now, so this won't be updated. It's open source, so if somebody wants to take it over, feel free!